High frequency antenna



FIG. 1 is a front elevation view of a high frequency antenna showing my new design;

FIG. 2 is a rear elevation view thereof; and,

FIG. 3 is a front perspective view thereof attached to a roll of labels.

The broken lines in FIG. 3 depict environment only and form no part of the claimed design. 

The ornamental design for a high frequency antenna, as shown and described. 